Lung compliance simulation system and associated methods

ABSTRACT

A patient simulator system for teaching patient care is provided. The system includes a patient simulator. The patient simulator includes a patient body comprising one or more simulated body portions. The one or more simulated body portions include a lung compliance simulation system in some instances. In that regard, the lung compliance system is configured to be used with an external ventilator, including positive end-expiratory pressure (PEEP) and assisted-control ventilation. In some instances, the lung compliance system includes a lung compartment, a simulated lung positioned within the lung compartment, where the lung compartment defines an available volume for the simulated lung to expand into and where the available volume for the simulated lung to expand into is adjustable to control a compliance of the simulated lung.

PRIORITY DATA

The present application is a continuation application of U.S.Nonprovisional patent application Ser. No. 13/975,997 filed Aug. 26,2013, which is a continuation of U.S. Nonprovisional patent applicationSer. No. 13/031,116, filed Feb. 18, 2011, which are incorporated byreference in its entirety.

BACKGROUND

The present disclosure relates generally to interactive educationsystems for teaching patient care. While it is desirable to trainmedical personnel in patient care protocols before allowing contact withreal patients, textbooks and flash cards lack the important benefits tostudents that can be attained from hands-on practice. On the other hand,allowing inexperienced students to perform medical procedures on actualpatients that would allow for the hands-on practice cannot be considereda viable alternative because of the inherent risk to the patient.Because of these factors patient care education has often been taughtusing medical instruments to perform patient care activity on asimulator, such as a manikin. Examples of such simulators include thosedisclosed in U.S. patent application Ser. No. 11/952,559 (PublicationNo. 20080138778), U.S. patent application Ser. No. 11/952,606(Publication No. 20080131855), U.S. patent application Ser. No.11/952,636 (Publication No. 20080138779), U.S. patent application Ser.No. 11/952,669 (Publication No. 20090148822), U.S. patent applicationSer. No. 11/952,698 (Publication No. 20080138780), U.S. Pat. No.7,114,954, U.S. Pat. No. 6,758,676, U.S. Pat. No. 6,503,087, U.S. Pat.No. 6,527,558, U.S. Pat. No. 6,443,735, U.S. Pat. No. 6,193,519, andU.S. Pat. No. 5,853,292, each herein incorporated by reference in itsentirety.

While these simulators have been adequate in many respects, they havenot been adequate in all respects. Therefore, what is needed is aninteractive education system for use in conducting patient care trainingsessions that is even more realistic and/or includes additionalsimulated features.

SUMMARY

The present disclosure provides interactive education systems,apparatus, components, and methods for teaching patient care.

In one embodiment, a system for teaching patient care is provided. Thesystem includes a patient simulator with a patient body comprised of oneor more simulated body portions. The one or more simulated body portionsinclude at least one simulated finger that is configured to interfacewith a pulse oximeter to simulate an oxygen saturation of the patientsimulator. In some instances, the simulated finger is further configuredto interface with the pulse oximeter to simulate a pulse rate of thepatient simulator. In some embodiments, the simulated finger includes afirst sensor for receiving a first wavelength of light from the pulseoximeter, a second sensor for receiving a second wavelength of lightfrom the pulse oximeter, and at least one light emitter for producinglight at the first and second wavelengths to simulate the oxygensaturation of the patient simulator. In some instances, the at least onelight emitter is positioned opposite the first and second sensors withinthe simulated finger. In that regard, the at least one light emitter canbe separated from the first and second sensors by a divider thatisolates the first and second wavelengths of light received from thepulse oximeter from the at least one light emitter. In some instances,the at least one light emitter is in communication with a processingunit configured to control the amount of light produced by the at leastone light emitter at the first and second wavelengths in order tosimulate the oxygen saturation of the patient simulator. The processingunit is positioned remote from the simulated finger in some instances.

In another embodiment, at least one simulated finger configured tointerface with a pulse oximeter to simulate an oxygen saturation of apatient simulator is provided. The at least one simulated fingerincludes a first sensor for receiving a first wavelength of lightemitted from the pulse oximeter, a second sensor for receiving a secondwavelength of light emitted from the pulse oximeter, and a light emitterfor emitting light at the first and second wavelengths from the at leastone simulated finger towards a receiver of the pulse oximeter such thatlight received by the receiver of the pulse oximeter simulates theoxygen saturation of the patient simulator. In some instances, the firstwavelength of light is between about 630 nm and about 700 nm and thesecond wavelength of light is between about 800 nm and about 1000 nm. Insome embodiments, the light emitter includes a light emitting diode andan associated fiber optic cable. The light emitter is positionedopposite the first and second sensors within the at least one finger insome embodiments. In one particular embodiment, the light emitter andthe first and second sensors are separated by a divider that isolatesthe first and second wavelengths of light emitted from the pulseoximeter from the receiver of the pulse oximeter when the pulse oximeteris positioned on the at least one simulated finger. The first and secondsensors are mounted to the divider in some instances. In someembodiments, the light emitter is in communication with a processingunit that controls the amount of light produced by the at least onelight emitter at the first and second wavelengths in order to simulatethe oxygen saturation of the patient simulator. In that regard, theprocessing unit may be programmable to allow calibration of the amountof light produced by the at least one light emitter to match settings ofthe pulse oximeter such that a measured simulated oxygen saturation ofthe patient simulator as measured by the pulse oximeter matches adesired simulated oxygen saturation of the patient simulator. In thatregard, the processing unit is programmable via a user interface in someinstances. In some embodiments, the user interface is computer based andmay be part of an overall user interface for controlling various aspectsof the patient simulator.

In another aspect, a system for teaching patient care is provided. Thesystem includes a simulated umbilicus. The simulated umbilicus includesa flexible elongated body defining three passageways along its length,where the three passageways simulate a vein and a pair of arteries. Areservoir housing a fluid is in fluid communication with the threepassageways of the flexible elongated body. Further, an actuatorpositioned adjacent to the reservoir and configured to control a flow ofthe fluid between the reservoir and the three passageways to simulate anumbilical pulse. In some instances, the actuator includes an air valve.In some instances, the actuator further includes a bellow such thatactuation of the air valve selectively inflates and deflates the bellowto control the flow of the fluid between the reservoir and the threepassageways. In some instances, the bellow is configured to compress thereservoir when the bellow is inflated in order to urge fluid out of thereservoir and into the passageways. In some embodiments, the simulatedumbilicus is sized and shaped for insertion into an opening in a torsoof a patient simulator, such as a newborn patient simulator. In thatregard, the simulated umbilicus may be a disposable component of thepatient simulator. In some instances, the newborn patient simulator isconfigured for use with a maternal patient simulator in order tosimulate a child birthing scenario. In some embodiments, each of thethree passageways may be cannulated using standard techniques forcannulating a vein or artery of a natural umbilicus. The simulatedumbilicus may be used to train medical personnel on a proper techniquefor cutting a natural umbilicus. In some instances, the simulatedumbilicus is configured for use with an umbilical clamp such that whenthe umbilical clamp is properly applied to the flexible elongated bodythe umbilical clamp prevents the fluid from the reservoir flowingdistally beyond the umbilical clamp.

In another embodiment, an apparatus is provided. The apparatus comprisesa flexible elongated body sized and shaped to simulate a naturalumbilicus. The flexible elongated body extends from a proximal portionto a distal portion and has three passageways extending along a majorityof a length of the flexible elongated body. The three passageways of theflexible elongated body simulate a vein and a pair of arteries of thenatural umbilicus. The apparatus further includes a reservoir positionedadjacent to the proximal portion of the flexible elongated body. Thereservoir houses a fluid and is in fluid communication with the flexibleelongated body. A flow of the fluid between the reservoir and theflexible elongated body simulates an umbilical pulse. In some instances,the flexible elongated body is configured for use with an umbilicalclamp such that when the umbilical clamp is properly applied to theflexible elongated body the umbilical clamp prevents the fluid fromflowing distally beyond the umbilical clamp. Further, in some instances,each of the three passageways may be cannulated using standardtechniques for cannulating a vein or artery of a natural umbilicus. Insome embodiments, the flexible elongated body is configured to trainmedical personnel on a proper technique for cutting a natural umbilicus.In some embodiments, the apparatus includes an actuator movable toselectively actuate the flow of the fluid between the reservoir and theflexible elongated body to simulate the umbilical pulse. In that regard,the actuator comprises an inflatable member positioned adjacent to thereservoir such that inflation of the inflatable member causes theinflatable member to compress at least a portion of the reservoir insome embodiments.

In another embodiment, an epidural training device is provided. Theepidural training device includes a simulated skin layer, a simulatedfat layer, a simulated tissue layer, and at least one simulatedvertebra. At least a portion of the simulated tissue layer and thesimulated vertebra define a cavity simulating an epidural space. In someinstances, the simulated tissue layer includes simulated muscle tissueand/or simulated connective tissue. In some embodiments, the cavitysimulating the epidural space is configured to receive a fluidinjection. In some instances, the simulated tissue layer comprises amixture of a silicone foam and a silicone oil. In some instances, thesimulated skin layer comprises a silicone thermoset. In some instances,the epidural training device is sized and shaped for insertion into anopening in a lumbar region of a patient simulator. The epidural trainingdevice includes a mechanism for indicating injection of an epiduralneedle outside of a desired epidural path. In some instances, themechanism is configured to activate at least one of a visual signal andan audible signal upon the epidural needle going outside of the desiredepidural path. In some embodiments, the mechanism includes a sensor fordetecting a position the epidural needle.

In another embodiment, a patient simulator is provided. The patientsimulator includes a simulated portion of a lumbar spine defining asimulated epidural space. The simulated portion of the lumbar spine isformed of materials mimicking at least the tactile characteristics of anatural lumbar spine such that injection of an epidural needle into thesimulated portion of the lumbar spine mimics a tactile feel associatedwith injection of the epidural needle into the natural lumbar spine. Thesimulated portion of the lumbar spine includes a simulated skin layer, asimulated fat layer, a simulated tissue layer, and at least onesimulated lumbar vertebra in some instances. In some embodiments, thepatient simulator is a maternal simulator with movable leg portions. Insome instances, the simulated portion of the lumbar spine is a removableportion of the patient simulator. In that regard, the patient simulatormay include a recess sized and shaped to receive the simulated portionof the lumbar spine.

In another embodiment, a method of simulating an epidural injection isprovided. The method includes obtaining a simulated portion of a lumbarspine defining a simulated epidural space. The simulated portion of thelumbar spine is formed of materials mimicking at least the tactilecharacteristics of a natural lumbar spine such that injection of anepidural needle into the simulated portion of the lumbar spine mimics atactile feel associated with injection of the epidural needle into thenatural lumbar spine. The method further includes injecting an epiduralneedle into the simulated portion of the lumbar spine to simulate anepidural injection. In some instances, the method includes actuating awarning signal if the epidural needle is positioned outside of a desiredepidural path. In some embodiments, actuating the warning signalcomprises generating at least one of a visual signal and an audiblesignal. In some instances, the method includes removing a plunger fromthe epidural needle and attaching a catheter to the epidural needle.

In another embodiment a system for teaching patient care is provided.The system comprises a patient simulator that includes a patient bodyhaving one or more simulated body portions. The one or more simulatedbody portions includes at least one simulated arm portion. The at leastone simulated arm portion is configured to interface with a standardblood pressure cuff to simulate a blood pressure of the patientsimulator. In some instances, the at least one simulated arm portionincludes a sensor for monitoring a force applied to the arm by the bloodpressure cuff. The sensor is a load sensor, pressure sensor, or othersuitable sensor. In one embodiment, the sensor is a load sensor anddeflection of a portion of the load sensor is indicative of the pressureapplied to the arm. In some instances, the sensor is positioned beneatha simulated skin layer of the at least one simulated arm portion.Further, in some embodiments the sensor is in communication with aprocessing module. The processing module may be programmable tocoordinate the force applied to the arm by the blood pressure cuff asmeasured by the sensor with a corresponding pressure measurement of theblood pressure cuff. In some instances, the processing module controlsproduction of one or more sounds based on the force applied to the armby the blood pressure cuff. For example, the one or more sounds mayinclude Korotkoff sounds, brachial pulse, radial pulse, and otherrelated blood pressure sounds. In that regard, the at least onesimulated arm portion includes one or more speakers for producing theone or more sounds in some instances. The processing module ispositioned remote from the at least one simulated arm portion in someembodiments.

In another embodiment an apparatus comprises a simulated arm configuredto interface with a standard blood pressure cuff such that a simulatedblood pressure of the simulated arm is measurable by the standard bloodpressure cuff. The simulated arm includes a load sensor for monitoring apressure applied to the simulated arm by the standard blood pressurecuff. The simulated arm is attached to a simulated torso of a patientsimulator in some embodiments. A processing module in communication withthe load sensor in some instances. In that regard, the processing modulemay be programmable to correlate the pressure applied to the simulatedarm by the standard blood pressure cuff with a pressure reading of thestandard blood pressure cuff. The processing module is positioned withinthe simulated arm in some instances. The processing module isprogrammable through a computer-based user interface, such as a patientsimulator user interface, in some embodiments.

In another aspect of the present disclosure, a method includes obtaininga simulated arm configured to interface with a standard blood pressurecuff such that a simulated blood pressure of the simulated arm ismeasurable by the standard blood pressure cuff, the simulated armincluding a load sensor for monitoring a pressure applied to thesimulated arm by the standard blood pressure cuff; interfacing astandard blood pressure cuff with the simulated arm; and utilizing thestandard blood pressure cuff while interfaced with the simulated arm totake the simulated blood pressure of the simulated arm. In someinstances, the method also includes correlating the pressure applied tothe simulated arm by the standard blood pressure cuff with a pressurereading of the standard blood pressure cuff for at least two differentpressures.

In accordance with another embodiment of the present disclosure, asystem for teaching patient care is provided. The system includes a lungcompliance simulation system. The lung compliance simulation systemcomprises a lung compartment and a simulated lung positioned within thelung compartment. The simulated lung is inflatable and deflatable. Thelung compartment defines an available volume for the simulated lung toexpand into and the available volume is adjustable to control acompliance of the simulated lung. The lung compliance simulation systemfurther includes a compression bag positioned within the lungcompartment adjacent to the simulated lung in some instances. Thecompression bag is inflatable and deflatable to adjust the availablevolume for the simulated lung to expand into. The compression bag is influid communication with a source of pressurized air in some instances.In some embodiments, the lung compliance system further includes acontrol valve for controlling an air pressure within the compressionbag. The control valve is positioned between the compression bag and thesource of pressurized air in some instances. In some embodiments, thelung compliance system is positioned within a patient simulator. Thepatient simulator includes a simulated head having at least one of asimulated mouth and a simulated nose in some instances. In that regard,in some embodiments the patient simulator further includes a simulatedairway connecting the simulated lung to at least one of the simulatedmouth and the simulated nose. Further, the patient simulator and thelung compliance system are configured to interface with a ventilator insome instances. In one particular embodiment, the ventilator is a bagvalve mask.

In another embodiment, an apparatus comprises: a lung compartmentdefining a maximum volume; a first bag positioned within the lungcompartment, the first bag being inflatable and deflatable to simulatefunctioning of a natural lung; a second bag positioned within the lungcompartment adjacent to the first bag, the second bag being inflatableand deflatable to occupy varying amounts of the maximum volume in orderto control a simulated lung compliance of the first bag. The first andsecond bags are formed of latex in some instances. The lung compartmentis formed of a material that is less flexible than latex in someinstances. Generally, increasing the amount of the maximum volumeoccupied by the second bag decreases the simulated lung compliance ofthe first bag, while decreasing the amount of the maximum volumeoccupied by the second bag increases the simulated lung compliance ofthe first bag. In some instances, the apparatus includes a control valvein communication with a source of pressurized air and the second bagthat controls a volume of the second bag.

In another embodiment, a patient simulator includes right and left lungcompliance simulations. For example, one patient simulator is comprisedof: a right lung compartment; a simulated right lung positioned withinthe right lung compartment, the simulated right lung being inflatableand deflatable to simulate functioning of a natural lung; a rightcompression bag positioned within the right lung compartment adjacent tothe simulated right lung, the right compression bag being inflatable anddeflatable to occupy varying amounts of the right lung compartment inorder to control a right lung compliance of the simulated right lung; aleft lung compartment; a simulated left lung positioned within the leftlung compartment, the simulated left lung being inflatable anddeflatable to simulate functioning of a natural lung; and a leftcompression bag positioned within the left lung compartment adjacent tothe simulated left lung, the left compression bag being inflatable anddeflatable to occupy varying amounts of the left lung compartment inorder to control a left lung compliance of the simulated left lung. Insome instances, the patient simulator further includes a control valvein communication with a source of pressurized air that controls a volumeof each of the right and left compression bags. Further, in someinstances the simulated right lung and the simulated left lung are eachin communication with a simulated airway. The simulated airway leads toat least one of a simulated mouth and a simulated nose in someembodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present disclosure will becomeapparent in the following detailed description of illustrativeembodiments with reference to the accompanying of drawings, of which:

FIG. 1 is a perspective view of a patient simulator incorporatingaspects of the present disclosure.

FIG. 2 is a perspective view of the patient simulator of FIG. 1, butwith a front cover of the simulator removed.

FIG. 3 is a perspective view of a portion of the patient simulator ofFIG. 1 illustrating a cervix of the patient simulator.

FIG. 4 is a perspective view of a portion of the patient simulator ofFIG. 1 illustrating aspects of a simulated birth.

FIG. 5 is a cross-sectional side view of a finger of the patientsimulator of FIG. 1 illustrating oxygen saturation simulation componentsaccording to one aspect of the present disclosure.

FIG. 6 is a front view of an arm of the patient simulator of FIG. 1illustrating blood pressure simulation components according to oneaspect of the present disclosure.

FIG. 7 is a side view of the arm of FIG. 6.

FIG. 8 is a diagrammatic schematic view of blood pressure simulationcomponents that may be incorporated into the arm shown in FIGS. 6 and 7according to one aspect of the present disclosure.

FIG. 9 is a rear view of a patient simulator with an epidural insertaccording to one embodiment of the present disclosure.

FIG. 10 is a perspective view of a portion of the patient simulator andthe epidural insert of FIG. 9.

FIG. 11 is a side view of an epidural insert according to one aspect ofthe present disclosure.

FIG. 12 is a perspective view of a patient simulator incorporatingaspects of the present disclosure.

FIG. 13 is a partial cutaway perspective view of a simulated umbilicusof the patient simulator of FIG. 9.

FIG. 14 is a diagrammatic schematic view of a lung compliance systemaccording to another aspect of the present disclosure.

FIG. 15 is a diagrammatic schematic view of a base portion of anepidural and lumbar puncture task trainer according to one embodiment ofthe present disclosure.

FIG. 16 is a diagrammatic schematic view of a base portion of anepidural and lumbar puncture task trainer similar to that of FIG. 15,but illustrating an alternative embodiment of the present disclosure.

FIG. 17 is a perspective view of a molding system in a separated stateaccording to one embodiment of the present disclosure.

FIG. 18 is a perspective view of the molding system of FIG. 17 in anassembled state.

FIG. 19 is a diagrammatic schematic view of a lung compliance systemaccording to another embodiment of the present disclosure.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of thepresent disclosure, reference will now be made to the embodimentsillustrated in the drawings, and specific language will be used todescribe the same. It will nevertheless be understood that no limitationof the scope of the disclosure is intended. Any alterations and furthermodifications in the described devices, instruments, methods, and anyfurther application of the principles of the disclosure as describedherein are contemplated as would normally occur to one skilled in theart to which the disclosure relates. In particular, it is fullycontemplated that the features, components, and/or steps described withrespect to one embodiment may be combined with the features, components,and/or steps described with respect to other embodiments of the presentdisclosure.

Referring now to FIGS. 1, 2, 3, and 4, shown therein is a patientsimulator 100 illustrating aspects of the present disclosure. As bestseen in FIG. 2, the patient simulator 100 includes a maternal simulator102 and a fetal simulator 104. FIG. 1 is a perspective view of thepatient simulator 100 with the fetal simulator 104 within the maternalsimulator; FIG. 2 is a perspective view of the patient simulator 100similar to FIG. 1, but illustrating the fetal simulator 104 disposedwithin the maternal simulator; FIG. 3 is a perspective view of an innerportion of the maternal simulator 102 illustrating a distensible cervixaccording to one embodiment of the present disclosure; and FIG. 4 is aperspective view of the patient simulator 100 illustrating a simulatedbirth of the fetal simulator 104 through the cervix of the maternalsimulator 102.

It is understood that the illustrated embodiment of the patientsimulator 100 is sized and shaped to represent a patient that willreceive treatment. In that regard, the patient simulator can take avariety of forms, including a manikin sized and shaped to represent maleor female patients of any size, age, and/or health, ranging frompremature fetus to full-sized adults. Further, the patient simulator mayinclude only a portion of the simulated patient (e.g., specific bodyparts or combinations of body parts). Accordingly, while aspects of thepresent disclosure are described with respect to particular embodimentsof patient simulators, no limitation is intended thereby. It isunderstood that the features of the present disclosure may beincorporated into or utilized in conjunction with any suitable patientsimulators. In some instances, aspects of the present disclosure areconfigured for use with the simulators and the related featuresdisclosed in U.S. patent application Ser. No. 11/952,559 (PublicationNo. 20080138778), U.S. patent application Ser. No. 11/952,606(Publication No. 20080131855), U.S. patent application Ser. No.11/952,636 (Publication No. 20080138779), U.S. patent application Ser.No. 11/952,669 (Publication No. 20090148822), U.S. patent applicationSer. No. 11/952,698 (Publication No. 20080138780), U.S. Pat. No.7,114,954, U.S. Pat. No. 6,758,676, U.S. Pat. No. 6,503,087, U.S. Pat.No. 6,527,558, U.S. Pat. No. 6,443,735, U.S. Pat. No. 6,193,519, andU.S. Pat. No. 5,853,292, each herein incorporated by reference in itsentirety.

Referring more specifically to FIG. 1, the maternal simulator 102 has ahead 106, with hair 108, eyes 110, a nose 112, a mouth 114, and ears116. A neck 118 connects the head 106 of the maternal simulator 102 to atorso 120. A left arm 122 and a right arm 124 extend from the torso 120.The left arm 122 includes an upper portion 126 and a lower portion 128with a hand 130 extending from the lower portion. The hand 130 fingers132, including an index finger 134 that will be discussed in greaterdetail below, and a thumb 136. In the illustrated embodiment, the upperportion 126 includes a sensor 138 that will be discussed in greaterdetail below. In some instances, the left arm 122 includes an IVreceptacle 140 capable of accepting injected medications. In someinstances, an RFID reader is positioned adjacent to the IV receptaclesuch that an RFID tag associated with an injected medication is read bythe RFID reader. In some embodiments, the RFID reader can thencommunicate the injected medication to a control unit of the patientsimulator 100. In that regard, in some instances the RFID reader alsocommunicates the amount or dosage of injected medicine. In someembodiments, the right arm 124 is substantially similar to the left arm122. In other embodiments, the right arm 124 contains more or lessfeatures than the left arm. In that regard, it is understood that anycombination of the features disclosed herein may be utilized in an armof a patient simulator in accordance with the present disclosure.

The torso 120 includes breasts 140 and an abdomen portion 142. Theabdomen portion 142 includes a cover 144. In that regard, the cover 144may be attached to the torso 120 via fastening means, such as snaps,hook and loop closures, buttons, adhesives, or other releasableattachment devices. As shown in FIG. 2, in some instances the cover 144covers a cavity 146 in the torso 120 that houses various components ofthe patient simulator 100. In that regard, in the illustrated embodimentthe fetal simulator 104 is positioned within the cavity 146 along withcomponents 148 for controlling movement of the fetal simulator 104. Inthat regard, the components 148 are configured to selectively rotate,translate, and release the fetal simulator 104 in order to simulate oneor more birthing scenarios. In some instances, the components 148 arefurther configured to monitor forces exerted on the fetal simulatorduring the one or more birthing scenarios.

Further, in some instances the components 148 are configured toselectively hold or release the fetal simulator 104 in order to simulateparticular birthing scenarios, including but not limited to shoulderdystocia, assisted deliveries (e.g., forceps or vacuum), and breechdeliveries. In some instances, the components 148 are configured to holdor maintain the fetal simulator 104 within the maternal simulator 102,or at least provide tension or resistance to removal of the fetalsimulator 104 from the maternal simulator 102 in order to providetactile sensation similar to a natural child birth. In that regard, insome instances the components 148 provide the proper tactile sensationfor a particular sized fetus (e.g., average size for 40 weeks, 36 weeks,32 weeks, 28 weeks, or other age) regardless of the actual size of thefetal simulator 104. In this manner, a single fetal simulator may beutilized to simulate a wide-range of birthing scenarios with fetuses ofdifferent ages and corresponding sizes. Alternatively, a plurality offetal simulators of varying sizes may be provided for use with thematernal simulator 102. In some instances, the components 148 and/orother aspect of the maternal simulator 102 or related software orhardware is capable of automatically detecting the size of the fetalsimulator 104 being utilized and simulates the corresponding birthingscenarios appropriately. In other instances, a user inputs the size ofthe fetal simulator being utilized.

In one embodiment, the cover 144 is configured to simulate contractionsof the maternal simulator 102. In that regard, all or portions of thecover 144 are selectively made to feel harder or firmer to simulate acontraction. Various mechanisms may be utilized to simulate thecontractions. In one embodiment, the cover 144 is in communication witha means for producing a vacuum such that activation of the vacuumcreates tension across a portion of the cover making it feel harder. Inanother embodiment, the cover 144 includes a bladder that is incommunication with a means for controlling the pressure within thebladder (e.g., an air compressor or fluid reservoir) for selectivelyincreasing and decreasing the pressure in the bladder to simulate thecontractions of the maternal simulator 102. It is understood thatdifferent levels of hardness may be produced to simulate differentlevels of contraction strength, for example, mild, moderate, and strongcontractions. Further, it is understood that the timing of thecontractions may be varied to appropriately simulate various birthingscenarios. Generally, the cover 144 is designed to obscure visualizationof the fetal simulator 104 within the maternal simulator 102 to moreaccurately simulate the child birthing process, and more realisticallychallenge the user's diagnostic abilities.

In some embodiments, the maternal simulator 102 is tetherless. That is,the maternal simulator 102 is functional without wired or tubularconnection to other devices outside of the simulator and, therefore,does not require wires, tubes, or other lines extending from thematernal simulator in order to be fully functional. Rather, the maternalsimulator 102 is self-contained. Thus, the maternal simulator 102 caninclude an internal power supply, such as a rechargeable power cell, andall pneumatic and fluid connections are made to the correspondingcompressors or other devices within the maternal simulator 102. As thematernal simulator 102 is self-contained, it is not only portable, butcan be in use while being transported between different locations.Further, in such embodiments, the maternal simulator 102 may communicatewith other devices, such as a control interface, through wirelesscommunication. Thus, the entire simulator system can be functional up tothe limits of the wireless communication. Further, in some embodimentsthe maternal simulator 102 connects wirelessly to a computer or networksystem, which then connects to other remote devices via a wired orwireless network, making the functional distance of the maternalsimulator 102 virtually limitless. Similarly, in some embodiments whenthe fetal simulator 104 is used in as a newborn after being birthed fromthe maternal simulator 102, it is operable in a tetherless mode as well.

Referring more particularly to FIGS. 3 and 4, the maternal simulator 102includes a birth canal 150 for the fetal simulator 104 to pass throughto simulate a natural birth. In that regard, the birth canal 150includes a distensible cervix 152 as well as flaps 154 and 156. In someinstances, the flaps 154, 156 are configured to interface with a portionof the maternal simulator 102 in order to maintain the cervix's relativeposition in the cavity 146. As such, in some instances the flaps 154,156 include snaps, hook and loop closures, and/or other reversiblefastening means for securing at least the cervix 152 to the maternalsimulator 102. In some embodiments, the flaps are sized and shaped tosimulate corresponding anatomical features such as ovaries, fallopiantubes, and surrounding tissues. The cervix 150 defines an expandableport 158 through which the fetal simulator 104 will be birthed. In someinstances, the port 158 expands from an initial configuration having adiameter of about 2 centimeters to a fully dilated configuration havinga diameter between about 8 centimeters and about 12 centimeters. In someinstances, in the fully dilated configuration the port 158 diameter isapproximately 10 centimeters. While the size of the port 158 has beendescribed in terms of a diameter, it is understood that the port 158does not necessarily have a circular profile, but instead may have anoblong and/or irregular shape.

The cervix 150 is disposed in a pelvic area of the maternal simulator102 that includes anatomical features simulating the natural pelvicarea. For example, in some instances, the pelvic area includes a pubicbone area 160 and a vulva 162. It is understood that the pelvic mayinclude features simulating a urinary tract, rectum, or other anatomicalfeatures. In that regard, the pubic bone area 160, the vulva 162, and/orother portions of the pelvic area may be inserts or components that arereplaceable with other inserts or components for displaying variouspatient conditions.

During a birthing simulation, the fetal simulator 104 moves through thecervix 150 and out of the vulva 162. In that regard, the cervix 150dilates from about one centimeter to about ten centimeters in diameteras the fetal simulator 104 is birthed. Because of the shape of the fetalsimulator's head 166, and the elasticity of the cervix 150, dilation isautomatically simulated coincident to the fetal descent. Accordingly, auser may practice measuring cervical dilation and plot labor progress asa Partograph. The elasticity of the cervix 150 may be adjusted, forexample by using thicker or thinner wall material, to produce a cervixhaving faster or slower dilation than normal, respectively. The vulva162 is made of a flexible material so that the user may manipulate thevulva and/or perform an episiotomy to birth the fetal simulator 104.Further, after delivery, the user may practice postpartum exercises,such as massaging a uterus insert (not depicted) back to a desirablesize, removing retained placenta parts (not depicted), or repairing thecervix 150 and/or vulva 162.

In some instances, the cervix 150 and/or vulva 162 are made of materialsthat mimic the corresponding natural human tissue. In one embodiment, apolysiloxane mixture for simulating human biological tissue is utilized.The mixture includes a silicone foam and a silicone oil, where thesilicone foam and the silicone oil are combined in a manner such thatthe resulting mixture has physical material properties simulatingnatural human biological tissue. In some instances, the silicone foam ispresent in an amount of about 10 to 45 percent by weight of the totalmixture weight, while the silicone oil is present in an amount of about55 to 90 percent by weight of the total mixture weight. In oneparticular instance, the silicone foam is present in an amount of about25 percent by weight of the total mixture weight, while the silicone oilis present in an amount of amount of about 75 percent by weight of thetotal mixture weight. In some instances, the polysiloxane mixturefurther comprises a silicone thermoset. In some embodiments, thesilicone foam and the silicone thermoset comprise a platinum catalyzedsilicone. Generally, the materials disclosed in U.S. Patent ApplicationNo. 61/305,982, titled “POLYSILOXANE MATERIALS AND METHODS THAT MIMICTISSUE”, U.S. patent application Ser. No. 13/031,102, filed Feb. 18,2011 (Publication No. 201102017104), and titled “BREAST TISSUE MODELS,MATERIALS, AND METHODS”, and U.S. patent application Ser. No. 13/031,087filed Feb. 18, 2011 (Publication No. 20110207103), and titled“ULTRASOUND PHANTOM MODELS, MATERIALS, AND METHODS”, each of which ishereby incorporated by reference in its entirety, may be utilized toform the cervix 150, vulva 162, and/or other tissue components of thematernal and/or fetal simulator.

Referring now to FIG. 5, shown therein is a diagrammatic cross-sectionalside view of a finger 134 of the patient simulator 102 of FIG. 1according to one aspect of the present disclosure. In that regard, thefinger 134 is shown with a pulse oximeter 170 attached thereto.Generally, the pulse oximeter 170 may be any commercially availablepulse oximeter. As discussed in greater detail below, the finger 134 canbe calibrated to properly interface with a particular pulse oximeter inorder to simulate an oxygen saturation and/or pulse rate of the patientsimulator. The pulse oximeter 170 is illustrated as a generic fingerpulse oximeter that includes an arm 172 for positioning on one side ofthe finger and an arm 174 opposite arm 172 for positioning on the otherside of the finger. The arms 172, 174 may be pivotally attached to oneanother to allow for movement during positioning of the oximeter 170onto the finger. The arm 172 includes an emitter 176, while the arm 174includes a receiver 178. In general, the oximeter 170 functions byemitting red and infrared light from the emitter 176 into the finger.Generally, the pulse oximeter 170 will emit a first wavelength of lightbetween about 630 nm and about 700 nm and a second wavelength of lightbetween about 800 nm and about 1000 nm. In a natural human finger, therelative absorption of the red and infrared light indicates the amountof oxygen in the blood. The relative absorption is determined by theamount of red an infrared light received at the receiver 178. The finger134 is able to simulate the absorption characteristics of a naturalhuman finger in order to allow a user to obtain oxygen saturation andpulse information for the patient simulator 102 utilizing the pulseoximeter 170.

In that regard, the simulated finger 134 includes a sensor 180 forreceiving infrared light emitted from the pulse oximeter and a sensor182 for receiving red light emitted from the pulse oximeter. The sensors180 and 182 are in communication with a processing unit 184. While thesensors 180 and 182 are shown to be in wired communication with theprocessing unit 184, it is fully contemplated that the sensors be inwireless communication with the processing unit 184. In that regard, theprocessing unit 184 is positioned within the finger 134 in someinstances. However, in other instances, the processing unit 184 isremote from the finger 134 and, in some instances, is even positionedoutside of the simulator 102. The processing unit 184 is generallyconfigured to control a light source 186. In some embodiments, the lightsource 186 is a red LED. The light source 186 is in opticalcommunication with a fiber optic cable 188. As such, the light emittedfrom the light source 186 travels through and is emitted from the fiberoptic cable 188. The fiber optic cable 188 is surrounded by a material190 that facilitates transmission of the light. In some instances, thematerial 190 is silicone. In that regard, the material 190 transmits thelight in such a manner that it is somewhat evenly transmitted across thesurface of the finger, which best simulates a natural finger and allowsfor steady readings by the oximeter 170. In order to prevent the lightemitted from the emitter 176 from reaching the receiver 178, the finger134 includes a barrier 192 that prevents transmission of the light fromthe emitter 176. In some embodiments, the barrier 192 is a PC board. Inthat regard, the barrier 192 may be utilized as a mount for the sensors180, 182 in some embodiments.

The processing unit 184 controls the intensity and timing of the lightsource 186 in order to simulate the oxygen saturation and/or pulse ofthe patient simulator 102. Due to the fact that different oximetermanufacturers utilized different wavelengths of the light, it isnecessary for the processing unit to be calibrated to function properlywith a particular pulse oximeter. In that regard, the processing unit184 may be programmable to facilitate calibration of the amount of lightproduced by the light source 186 in order to match the correspondingsettings of the pulse oximeter such that the oxygen saturation of thepatient simulator as measured by the pulse oximeter matches a desiredsimulated oxygen saturation of the patient simulator. Accordingly, insome instances, multiple calibration points are utilized to adjust therelative output of the light source 186 so that the desired simulatedoxygen saturation matches the oxygen saturation measured by the oximeter170. In some instances, the processing unit 184 and light source 186 arecalibrated at 100%, 80%, and 60% oxygen saturations. However, it isunderstood that any combination of points may be utilized to calibratethe processing unit 184 and light source 186 and that the greater thenumber of calibration points the more accurate overall the system islikely to be.

The processing unit 184 is programmable via a user interface in someinstances. In some embodiments, the user interface is computer based andmay be part of an overall user interface for controlling various aspectsof the patient simulator. The pulse of the patient simulator 102 issimulated by pulsing the light source at the desired heart rate. In thatregard, the pulse in the finger 134 is synchronized with the heart rateof the patient simulator 102. Generally, there is not a need tocalibrate the processing unit 184 to control the pulse rate fordifferent oximeters. However, it is possible to calibrate the pulserates utilizing calibration points (i.e., different beats per minute) ina similar manner to the levels of oxygen saturation if desired.

Referring now to FIGS. 6, 7, and 8, shown therein are aspects of theupper portion 126 of the left arm 122 of the patient simulator 102. Inthat regard, the arm 122 includes a sensor 138 that is utilized tosimulate a blood pressure of the patient simulator 102, includingsystolic and diastolic pressures. In that regard, the sensor 138 isconfigured to allow the blood pressure of the patient simulator 102 tobe taken using standard blood pressure cuffs. As shown, the sensor 138includes a main housing 200 and a sensing portion 202. The sensingportion 202 is capable of monitoring the pressure applied to the arm 122by a blood pressure cuff. In some instances, the sensing portion 202 isa load cell. In that regard, the amount of deflection of the load cellis based on the pressure applied to the arm 122. To achieve properdeflection of the load cell, the sensor 138 must be fixed relative tothe arm 122. In that regard, the sensor 138 includes a mountingextension 204 extending from the main body. The mounting extension 204receives a fastener 206. In the illustrated embodiment, the fastener 206is a screw that is mated with a nut 208. The sensor 138 includes anothermounting extension 210 substantially opposite mounting extension 204.Again, the mounting extension 210 receives a fastener 212, which in theillustrated embodiment is a screw that is mated with a nut 214. Themounting extensions 204, 210 and fasteners 206, 212, along with the nuts208, 214, are utilized to secure the sensor 138 in a fixed position onthe arm 122. It is understood, however, that a simulated layer of skinmay be present over the sensor 138 such that the sensor is not visibleto a user.

Generally, the sensing portion 202 can be calibrated such that ameasurement or deflection of the sensing portion 202 corresponds to apressure measurement of the blood pressure cuff. As shown in FIG. 8, thesensor 138 is in communication with a processing module 216 in someinstances. The processing module 216 is configured to monitor the loadsas measured by the sensing portion 202 in some instances. In thatregard, the processing module 216 is programmable to facilitatecoordination of a measured load or pressure with the correspondingpressure measurement of the blood pressure cuff. In general, the loadcell will produce a voltage output correlating to the measured pressure.In some instances, multiple calibration points are utilized to match thesensed values of the sensing portion 202 with the pressure readings ofthe blood pressure cuff based on the voltage outputs. It is understoodthat any number of sensed values for different pressure readings pointsmay be utilized to calibrate the processing module 216, but that thegreater the number of calibration points the more accurate overall thesystem is likely to be. The processing module 216 is programmable via auser interface in some instances. In some embodiments, the userinterface is computer based and may be part of an overall user interfacefor controlling various aspects of the patient simulator.

In some instances, the measurements of the sensor 138 are utilized todetermine when certain sounds should be produced by the simulator 102.For example, in some instances the measurements of the sensor 138 areutilized to determine when to play Korotkoff sounds. Further, thebrachial and radial pulses may cut off per the systolic and diastolicpressures of the patient simulator 102. In this regard, the processingmodule 216 may be in communication with another module or controller forproducing these various sounds. Alternatively, the processing module 216itself may control a speaker or speakers for producing these sounds. Inthis manner, the sensor 138 and related components of the patientsimulator 102 are utilized to allow a user to take the simulated bloodpressure of the patient simulator in a realistic manner utilizingstandard blood pressure cuffs, including tetherless blood pressurecuffs.

Referring now to FIGS. 9, 10, and 11, shown therein is an epiduralinsert 220 in accordance with one aspect of the present disclosure. Ingeneral the epidural insert 220 is configured to train medical personnelin the proper procedures for administering an epidural injection. As ageneral matter, epidural injections are the administration of medicationinto the epidural space of the spine. Epidural injections are used totreat swelling, pain, and inflammation associated with neurologicalconditions that affect nerve roots, such as a herniated disc, but isfrequently given during childbirth. Performing epidural injections is acomplex task that demands a high level of skill and precision from themedical personnel. An improperly performed epidural injection can resultin serious complications for the patient, including paralysis and, insome instances, death. Accordingly, the epidural insert 220 providesvital training without putting actual patients at risk.

In that regard, the epidural insert 220 is designed for learning,practicing, and experiencing the most common and important aspects ofthe epidural procedure, including identifying the appropriate locationfor insertion of the epidural needle, inserting the epidural needle,simulating the feel of passing the epidural needle through the differenttissue layers and into the epidural space, and injecting the fluid intothe epidural space. The realistic appearance, anatomically correctfeatures, and lifelike feel of the epidural insert 220 provide a tactilefeedback that substantially matches that of the natural anatomy. In thatregard, the epidural insert 220 can simulate loss of resistance whenusing air or saline within the epidural needles. Further, the epiduralinsert 220 can be utilized to train medical personnel on the techniquesfluid and dural taps. The epidural insert 220 provides safe means oftraining medical personnel how to properly perform epidural injectionsand provides realistic feedback to users on their technique.

As shown in FIGS. 9 and 10, in some instances the epidural insert 220 issized and shaped for insertion into a lower back of a patient simulator222. In particular, the epidural insert 220 is configured for insertioninto the lumbar region of the spine in some instances. Generally, thepatient simulator 222 includes at least a torso of the patient. In theillustrated embodiment, the patient simulator 222 includes a torso 224and leg portions 226, 228. In that regard, in some instances the torsoand leg portions 226, 228 are movable and bendable to allow forpositioning of the patient simulator 222. In that regard, in sometechniques the patient is asked to bend at the waste and/or bring herknees into her chest. Accordingly, in some instances the patientsimulator 222 is movable to allow such positioning. Further, the torso224 of the patient simulator 222 includes a recess or opening 230 sizedto receive the epidural insert 220. In some instances, the recess 230 ispositioned in the lumbar region of the spine. In the illustratedembodiment the recess 230 has a generally rectangular profile. However,it is understood that the recess 230 may take any shape, includinggeometrical and irregular shapes. The recess 230 is bounded by a surface232. In some instances, the surface 232 is a skin-deep recess. That is,the surface 232 is bounded by a rim or edge 234 that is generally thethickness of the skin of the simulator 222. In that regard, the epiduralinsert 220 includes a simulated skin layer 240 that includes an overhangor lip 242 sized and shaped to mate with the surface 232 such that whenthe epidural insert is received within the recess 230, the skin layer240 of the epidural insert and the skin layer of the torso aresubstantially aligned to form a continuous skin layer.

Referring more particularly to FIG. 11, the epidural insert 220accurately models the anatomical structure of the lumbar spine,including vertebrae, surrounding muscle, fat, and connective tissue. Inparticular, the epidural insert includes the skin layer or simulateddermis 240 as noted above. Below the skin layer 240, is a fat layer 244followed by a connective tissue layer 246 that includes simulatedligamentum flavum. Positioned within the connective tissue layer 246 aresimulated lumbar vertebrae 248, 250, and 252. In that regard, the lumbarvertebrae 248, 250, and 252 represent vertebrae L3, L4, and L5 in someinstances. In other instances, the epidural insert 220 includes othersimulated vertebrae (including lumbar and/or thoracic vertebrae) and/ora simulated sacrum. In another exemplary embodiment, the insert includessimulated vertebrae representative of vertebrae L2, L3, L4, and L5.

As a general matter, the epidural insert 220 simulates the feel ofrealistic tissue and the placement and relative dimensions accuratelyreflect true human anatomical structures. Accordingly, in someinstances, the insert 220 includes additional features and/or layers. Onthe other hand, in some instances, the insert 220 does not includeseparate fat and connective tissue layers 244, 246, but instead includesa general subcutaneous tissue layer. In that regard, in some instancesthe subcutaneous layer has varying material properties to simulate thecorresponding natural tissue. In other instances, the subcutaneous layerhas substantially uniform material properties throughout. The epiduralinsert 220 defines an epidural space that is hollow and serves asreservoir for receiving fluid injected from an epidural needle. In someinstances, the epidural space is in fluid communication with a drain ora larger reservoir that allows the fluid injected into the epiduralspace to be removed from the direct epidural space, which allowsinjection of additional fluid into the epidural space. This facilitatesmultiple epidural simulations with the insert 220 without the need todrain or remove the injected fluid from the insert and/or simulator.

Since the procedures related to epidural injections are largely based onfeel, the tactile characteristics of the materials utilized to form thevarious anatomical structures of the epidural insert 220 must mimictactile characteristics of the natural tissues to be an effectivetraining aid. In that regard, the lumbar vertebrae 248, 250, and 252 aremade of a hard material to realistically represent bone, such as a hardpolyurethane thermoset, Acrylonitrile butadiene styrene (ABS),polycarbonate, and high-density polyethylene (HDPE). Generally, thematerial has a shore hardness between about 50 D and about 90 D and,more specifically, between about 60 D and about 80 D in some instances.Further, the material is pigmented or colored to simulate naturalvertebrae in some embodiments. Generally, the vertebrae 248, 250, and252 include simulated spinous processes to allow a user to feel thevertebrae 248, 250, 252 through the skin and fat layers 140, 144 so thatthey can be used as reference points for determining the properplacement of the needle puncture.

The connective tissue layer 246 is made from a firm, but dense material,such as silicone thermoset. Generally, the material has a shore hardnessbetween about 10 A and about 50 A and, more specifically, between about20 A and 35 A in some instances. The fat layer 244 is soft andmalleable, offers low frictional resistance to injection, and has goodrebound and shape memory in some instances. The outer skin layer and/orthe underlying tissue layer(s) are formed from a material that mimicsthe natural human skin. In that regard, in some instances the outer skinlayer and/or the underlying tissue layer(s) are formed of materialsdisclosed in U.S. Patent Application No. 61/305,982, filed Feb. 19, 2010and titled “POLYSILOXANE MATERIALS AND METHODS THAT MIMIC TISSUE”, U.S.patent application Ser. No. 13/031,102, filed Feb. 18, 2011 (PublicationNo. 20110207104) and titled “BREAST TISSUE MODELS, MATERIALS, ANDMETHODS”, and U.S. patent application Ser. No. 13/031,087, filed Feb.18, 2011 (Publication No. 20110207103) and titled “ULTRASOUND PHANTOMMODELS, MATERIALS, AND METHODS”, each of which is hereby incorporated byreference in its entirety. In particular, in one specific embodiment,the outer skin layer 140 is formed of a silicone thermoset having aShore Hardness between about 00 and about 10 and the underlying tissuelayer(s) is formed of a combination of silicone foam, siliconethermoset, and silicone oil as disclosed in some embodiments of theabove-mentioned patent applications.

The materials of the epidural insert 220 allow it to be used many timeswithout adverse effect. Further, in some instances subsequent users willnot be able to tell where previous users have injected the needle. Thisis possible because of the superior self sealing characteristics of thesilicone mixtures. The silicone mixtures automatically seal and remainintact, even after numerous needle punctures. However, eventuallymaterials of the epidural insert 220 will give way and show signs ofwear and become unsuitable for training purposes. Accordingly, in someinstances, the epidural insert 220 is a disposable unit that is easilyreplaced by a user. Following extended use, the epidural insert 220 issimply lifted out of the recess 230 of the patient simulator 222 and areplacement epidural insert 220 is positioned within the recess.

To use the epidural insert 220, an operator first fills an epiduralneedle with air, saline solution, or other suitable fluid. The needle isplaced in the proper position by referencing the features of the lumbarvertebrae. The needle is then advanced while applying a light pressureon the syringe plunger. In some instances, a loss of resistance toinjection technique is used to identify the epidural space. The needleis inserted into the device, and when the tip of the needle enters aspace of negative or neutral pressure, i.e., the epidural space, thereis a loss of resistance and it will be easy to inject the fluid throughthe needle. The combination of materials and construction techniques inthe inventive device provide this tactile feedback. The user knows whenthe needle has entered the epidural space when they feel a light pop orclick as the needle breaches into the epidural space and the syringeplunger of the needle begins to yield to pressure.

Extreme caution must be exercised in the positioning of the needle intothe epidural space. In that regard, the user must stop immediatelywithin the narrow epidural space in order to avoid puncturing the duramater, which can cause grave patient complications in real lifesituations. In some instances, the epidural insert 220 includes amechanism for indicating injection of an epidural needle outside of adesired epidural path. In some instances, the mechanism is configured toactivate at least one of a visual signal and an audible signal upon theepidural needle going outside of the desired epidural path. In thatregard, the mechanism includes a sensor for detecting a position theepidural needle in some instances. In one embodiment, the sensorincludes a snap-action lever switch that is actuated upon contact by theneedle. In other instances, visual monitors are utilized to monitor theposition of the needle and/or activate an alert. Once the needle ispositioned within the epidural space, the syringe and plunger may beremoved and flexible catheter tubing inserted into the epidural needle.In typical use, the flexible catheter tubing would be used to injectadditional medication into the epidural space, if needed.

Referring now to FIGS. 12 and 13, shown therein is a newborn simulator300 incorporating a simulated umbilicus 302 according to one aspect ofthe present disclosure. In one embodiment, the newborn simulator 300 issubstantially the size of an average sized neonate of 28 weeksgestational age. In another embodiment, the newborn simulator 300 issubstantially the size of an average sized neonate of 40 weeksgestational age. Generally, the newborn simulator 300 exhibits manyphysiological characteristics, including heart rate, pulse, oxygenation,and a variety of body sounds that can be detected using the conventionalinstrumentation. In that regard, the umbilicus 302 is configured to bein sync with the other portions of the newborn simulator. For example,the umbilicus 302 is configured to simulate an umbilical pulse that istimed to coincide with the heart beat of the newborn simulator 300.

Referring more particularly to FIG. 13, the umbilicus 302 includes aflexible elongated body or tubing 304 having three passageways 306, 308,and 310 extending along its length. The three passageways 306, 308, and310 simulate a vein and a pair of arteries, respectively. In thatregard, in some instances the three passageways 306, 308, and 310 may becannulated using standard techniques for cannulating a vein or artery ofa natural umbilicus. In some instances, the three passageways 306, 308,and 310 are generally equally spaced about the circumference of thetubing 304, as shown at the end of the tubing 304 in FIG. 13. However,the three passageways 306, 308, and 310 may be spiraled within and alongthe length of the tubing. In that regard, the three passageways 306,308, and 310 are oriented to simulate the natural configuration of thevein and arteries of a natural umbilicus in some embodiments.

The three passageways 306, 308, and 310 are in fluid communication witha reservoir 312. In that regard, the reservoir 312 contains a fluid. Insome instances, the fluid within the reservoir 312 simulates blood ofthe umbilicus 302. Adjacent to the reservoir is an actuator 314. Theactuator 314 is configured to control a flow of the fluid between thereservoir 312 and the three passageways 306, 308, and 310 to simulate anumbilical pulse. Generally, the actuator 314 may be any suitablemechanism for controlling the flow of fluid to simulate the umbilicalpulse, include mechanical, pneumatic, electro-mechanical, and/orcombinations thereof. In one embodiment, the actuator includes an airvalve and an associated bellow, where actuation of the air valveselectively inflates and deflates the bellow to control the flow of thefluid between the reservoir 312 and the three passageways 306, 308, and310. In that regard, inflation of the bellow causes the bellow tocompress at least a portion of the reservoir 312 and urges fluid out thereservoir and into the passageways 306, 308, and 310, while deflation ofthe bellow allows the reservoir to expand back to its original state andallows the fluid to flow back into the reservoir.

In some instances, the umbilicus 302 is configured to train medicalpersonnel on a proper technique for cutting a natural umbilicus. In thatregard, in some instances the umbilicus 302 is configured for use withan umbilical clamp such that when the umbilical clamp is properlyapplied to the flexible elongated body the umbilical clamp prevents thefluid from the reservoir flowing distally beyond the umbilical clamp.Further, in some instances the umbilicus 302 is formed of a materialthat simulates a natural umbilicus in terms of the force needed to cutthe material.

In some instances, the umbilicus 302 is a disposable component of thenewborn simulator 300. In that regard, the newborn simulator 300includes a recess or opening for receiving the umbilicus 302.Accordingly, it is understood that one umbilicus is readily replaceablewith another umbilicus when necessary. Alternatively, the tubing 304 ofumbilicus may be a disposable component such that the tubing isreplaceable and the reservoir is refillable, if necessary, but theremaining parts of the umbilicus remain with the newborn simulator 300.

Referring now to FIG. 14, shown therein is a diagrammatic schematic viewof a lung compliance system 400 according to another aspect of thepresent disclosure. The lung compliance system 400 is configured tosimulate natural lung mechanics. In particular, the lung compliancesystem 400 is configured to simulate the natural lung mechanicsassociated with connecting natural lungs to external ventilators. As ageneral matter, lung compliance is a measure of air volume changerelative to applied pressure change. Lungs that stretch too much (tooflexible) are said to be high compliance lungs, whereas lungs thatstretch too little (too stiff) are said to be low compliance lungs. Thelung compliance system 400 facilitates simulation of normal, high, andlow compliance lungs. In that regard, the lung compliance system 400increases and decreases the volume capacity of one or more simulatedlungs to replicate natural lung compliance.

As shown, the lung compliance system 400 includes a right lungcompartment 402 and a left lung compartment 404. The right lungcompartment 402 contains a lung 406 and a compression bag 408, while theleft lung compartment 404 contains a lung 410 and a compression bag 412.Each of the lung compartments 402, 404 define a confined area thatcontains lungs 406, 410 and compression bags 408, 412, respectively. Insome instances, the lung compartments 402, 404 are formed of a fabric,plastic, polymer, or other material having minimal stretchability and/ora predetermined maximum volume such that the lung compartments 402, 404do not expand or stretch beyond the maximum volume, even duringinflation and deflation of the lungs 406, 410 and compression bags 408,412 as discussed below. The lungs 406, 410 and compression bags 408, 412are formed of latex or other flexible material that allows expansion andcontraction of the volume of the lungs and compression bags.

The lungs 406, 410 are connected to an airway 414. In particular, theright lung 406 is connected to the airway 414 through a branch 416,while the left lung 410 is connected to the airway 414 through a branch418. The airway 414 leads to an external orifice that is communicationwith an external ventilator 420. In some instances, the airway 414 leadsto an external orifice of a patient simulator, such as a simulated mouthand/or nose. In such instances, the interface or connection between theexternal ventilator 420 and the airway 414 via the external orifice(s)mimics the interface or connection between the external ventilator and anatural patient. In that regard, the external ventilator 420 isgenerally representative of any external ventilator that is utilized inmedical settings. As a general matter the lung compliance system 400 issuitable for use with all types of commercially available ventilators(including bag valve masks, as well as computerized or automatedventilators). Accordingly, the lung compliance system 400 is suitable totrain medical personnel on the proper manner of utilizing the particularventilator(s) used in the hospital or other medical setting in which themedical personnel will be working. Generally, the connections betweenthe external ventilator 420, the airway 414, the branches 416, 418, andthe lungs 406, 410 allow the transfer of air between the externalventilator 420 and the lungs 406, 410 to simulate assisted breathing.

The compression bags 408, 412, on the other hand, are connected to acompressed air source 422 via a variable pressure control valve 424. Inthat regard, the variable pressure control valve 424 controls the airpressure within the compression bags 408, 412 and, thereby, thecorresponding volumes of the bags. In that regard, as the compressionbags 408, 412 are expanded the available room within the compartments402, 404 for the lungs 406, 410 to expand is correspondingly reduced.Accordingly, lung compliance is varied by increasing/decreasing the airpressure inside the compression bags 408, 412 to provide the desiredamount of available volume within the compartments 402, 404 for thelungs 406, 410 to expand into. In that regard, as the pressure insidethe bags 408, 412 is increased, the volume of the compression bagsincreases, which decreases the available volume for the lungs 406, 410,which in turn simulates decreased lung compliance. On the other hand, asthe pressure inside the bags 408, 412 is decreased, the volume of thecompression bags decreases, which increases the available volume for thelungs 406, 410, which in turn simulates increased lung compliance.Accordingly, by adjusting the pressure and corresponding volume of thecompression bags, the size of lungs is similarly adjusted to simulatelung compliance from High to Normal to Low.

While the lung compliance system 400 is shown as having right and leftlung compartments, in other embodiments the system includes only asingle lung compartment. Further, while the compression bags 408, 412are shown as being connected to a single control valve 424, it isunderstood that the pressure within each of the compression bags 408,412 is controlled separately in some instances. In some such instances,the system includes a pair of control valves, each associated with oneof the compression bags. Alternatively, the single control valve 424 mayhave two or more outputs that are individually controlled to allowseparate control of the pressures within the compressions bags 408, 412.Further still, in some embodiments the compression bags 408, 412 arefilled with a liquid, instead of air or other gas. In other embodiments,the compression bags 408, 412 are replaced with a movable member thatselectively increases/decreases the available volume within lungcompartments 402, 404 for the lungs 406, 410. For example, in oneembodiment each of the lung compartments 402, 404 includes a movablewall that is connected to a motor, pneumatic valve, or other actuatorthat controls the position of the wall within the lung compartment.Movement of the wall selectively increases or decreases the volumewithin the lung compartment.

Referring now to FIG. 15, shown therein is a diagrammatic schematic viewof a portion of an epidural and lumbar puncture task trainer 500according to one embodiment of the present disclosure. In that regard,the task trainer 500 includes a back plate or simulated torso 502. Inthe present embodiment, the back plate 502 is only a portion of asimulated torso, which allows the task trainer 500 to be highly portabledue to its reduced size. In other embodiments, however, the back plate502 is part of a full-bodied manikin. Generally, the back plate 502includes critical anatomical landmarks for epidural and lumbar punctureprocedure, including the location of the iliac crests. The back plate502 of the task trainer 500 includes a recess or opening 504 sized andshaped to receive an epidural/lumbar puncture insert. In that regard,the epidural/lumbar puncture insert is similar to insert 220 describedabove in some instances. The opening 504 is positioned in a simulatedlumbar region of the spine. In the illustrated embodiment the opening504 has a generally rectangular profile. However, it is understood thatthe opening 504 may take any shape, including geometrical and irregularshapes. The opening 504 includes a depression 506 that is bounded by asurface 508 that is recessed with respect to the outer surface of theback plate 502. In some instances, the depression 506 has provisions(e.g., structure, recess, connectors, etc.) to orient a fluid-filledtubing that forms a simulated dura mater and cerebrospinal fluid, asdiscussed below. In some instances, the surface 508 is a skin-deeprecess. That is, the surface 508 is bounded by a rim or edge of the backplate 502 that is generally the thickness of the simulated skin of theback plate. In that regard, the epidural/lumbar puncture insert mayinclude a simulated skin layer that includes an overhang or lip thatsized and shaped to mate with the surface 508 such that when theepidural insert is received within the recess 504, the skin layer of theepidural/lumbar puncture insert and the skin layer of the back plate 502are substantially aligned to form a continuous skin layer. In someinstances, a structure (e.g., a fabric tab) is attached to the top sideof the insert to aid in removal of the epidural/lumbar puncture insertfrom the back plate 502.

In additional to the back plate 502 and the epidural/lumbar punctureinsert, the task trainer 500 includes a fluid supply system 510. In thatregard, the fluid supply system 510 allows the task trainer 500 to beused as both a lumbar puncture trainer and an epidural trainer. Thefluid supply system 500 includes a pressure source or fluid supply 512(e.g., a syringe assembly, an IV Bag assembly, or pump) and tubing 514in communication with the fluid supply 512 to simulate the dura materand subarachnoid space. In that regard, the tubing 514 is connected tothe fluid supply 512 via tubing 516, 518. In some instances, tubing 516,518 are integrally formed with one another and/or tubing 514. In otherinstances, one or more of tubing 514, 516, and 518 are separatecomponents that are connected to one another. The fluid supply systemalso includes additional tubing (not shown) to facilitatedrainage/venting tube. In that regard, the arrangement of the tubing andconnectors of the fluid supply system 500 allow the system to either beclosed or open. In that regard, an open system is typically needed whenfilling or draining the system of its simulated cerebrospinal fluid.During a procedure, a closed system is preferred so that the fluid loopcan be pressurized to a desired pressure (simulating either normal orabnormal CSF pressure). Further, sometimes it is desirable necessary tomeasure the Cerebrospinal Opening Pressure at the beginning of a LumbarPuncture Procedure. Accordingly, a closed loop that can be pressurizedto a desired level allows training of the measurement techniques. Byhaving the flexibility to change this pressure, a training session caninclude analysis of normal versus abnormal values of pressures.

In that regard, in some embodiments the task trainer 500 also includespressure measurement circuitry that in communication with the fluidsupply system 510 in order to accurately monitor and/or set the pressurewithin at least the tubing 514. In one embodiment, a pressure transduceris incorporated within the fluid loop and a display is provided toenable pressure readout. The display can include either an analog (e.g.,dial) or digital (e.g., LED) readout to show the pressure level. In someinstances, the pressure display is embedded in the side wall or othersurface of the back plate 502. Further, in some instance the pressuremeasurement circuitry allows the user to set the desired pressure and,in turn, controls the fluid supply system to achieve the set pressure.The fluid supply system and pressure measurement circuitry are batterypowered in some instances, allowing the system to be compact andportable. In other instances, the task trainer 500 utilizes line power.In some instances, a supporting stand is provided to mount the tasktrainer 500 on. In that regard, the stand allows the trainer to be usedin either a sitting position or a left lateral decubitus position.

FIG. 16 is a diagrammatic schematic view of an epidural and lumbarpuncture task trainer 520. Task trainer 520 is similar in many respectsto task trainer 500, but the fluid supply system is contained within abase 522 of the task trainer 520. In some instances, the base 522includes openings, compartments, and/or other structure sized and shapedto contain all of the necessary tubing and electronics of the tasktrainer. As shown, the base 522 of the task trainer 520 includes arecess or opening 524 that is sized and shaped to receive theepidural/lumbar puncture insert. The opening 524 includes a depression526 that is bounded by a surface 528 that is recessed with respect tothe outer surface of the base 502. The task trainer 520 also includes afluid supply system that allows the task trainer 500 to be used as botha lumbar puncture trainer and an epidural trainer. The fluid supplysystem 500 includes a pressure source or fluid supply 530 (e.g., asyringe assembly, an IV Bag assembly, or pump) and tubing 532 incommunication with the fluid supply to simulate the dura mater andsubarachnoid space. As shown, the entire fluid supply system 500 iscontained within the profile of the base 522.

Referring now to FIGS. 17 and 18, shown therein is a molding system 540according to one embodiment of the present disclosure. Morespecifically, FIG. 17 is a perspective view of the molding system 540 ina separated state, while FIG. 18 is a perspective view of the epiduralmolding system in an assembled state. In that regard, the molding system540 is particular suited for forming epidural/lumbar puncture inserts ofthe present disclosure. Both the lumbar vertebrae and theepidural/lumbar puncture insert assembly are manufactured in splitmolds. The lumbar vertebrae are manufactured in a split mold glove mold.Due to the complexity of the geometry, it is necessary to mold the rigidvertebrae within a flexible glove mold that is split into two halves forease of de-molding. An anatomical model forms the basis of the lumbarvertebrae, and a two-part glove mold is cast around the anatomicalmodel. In some instances, the glove mold is cast within a rectangularbox. As a result, the external geometry of the glove mold isrectangular, and the internal cavity follows the contours of theanatomical model. In some instances, the glove mold is manufactured froma platinum-cured silicone thermoset with a shore hardness between about10 A and about 30 A. In one embodiment, the glove mold is formed of asilicone thermoset with a shore hardness of 10 A (such as Dragon Skin®10 Medium, Smooth-On, Inc., Easton, Pa.).

Referring more specifically to FIG. 17, molding system 540 is shown withthe lumbar vertebrae 542 positioned between split mold portion 544 andsplit mold portion 546. In that regard, the split mold portions 544, 546that define the split mold for forming the epidural/lumbar punctureinsert assembly have complex geometries that work best when manufacturedusing a process such as rapid prototyping and/or direct metal lasersintering (DMLS). In the case of rapid prototyping, an ABS mold isproduced on a 3D printer. If DMLS is utilized, an aluminum mold isproduced. The split mold portions 544, 546 include a plurality oflocating projections that are utilized to couple the split mold portions544 and 546 to one another and to secure the lumbar vertebrae 542 inplace with respect to the split mold portions 544, 546. In theillustrated embodiment, projections 548 extending from split moldportion 544 will engage corresponding recesses in split mold portion546. Similarly, projections 552 extending from each of the split moldportions 544, 546 will engage corresponding recesses or depressions inthe lumbar vertebrae 542. In that regard, the locating projections 548and/or 552 are screws or other engaging structures in some instances.Referring to FIG. 18, the split mold portions 544, 546 are shownassembled with the lumbar vertebrae 542. The split mold arrangementallows de-molding of the assembly.

As discussed above with insert 220, the epidural/lumbar puncture insertsof the present disclosure consist of a skin layer, a subcutaneous layer,a simulated ligamentum flavum, and lumbar vertebrae (e.g., L2, L3, L4,and L5) whose properties are optimized to provide realistic tactilefeedback for the injection process. In some embodiments, the skin layeris manufactured from a platinum-cured silicone thermoset with a shorehardness between about 00-30 and about 30 A. In one embodiment, the skinlayer is formed of a silicone thermoset with a shore hardness of 10 A(e.g., Dragon Skin 10 Medium, Smooth-On, Inc., Easton, Pa.) includingpigments to provide a color match to the skin tone of the back plate. Insome embodiments, the subcutaneous layer is manufactured from a blend ofsilicone foam, silicone thermoset, and silicone oil. In someembodiments, the silicone foam (e.g., Soma Foama, Smooth-On, Inc.,Easton, Pa.) ranges from about 10% to about 40% of the total weight, thesilicone thermoset has a shore hardness of 00-10 (e.g., Silicone 99-255,Smooth-On, Inc., Easton, Pa.) and ranges from about 15% to about 65% ofthe total weight, and the silicone oil (e.g., TC-5005 C, BJBEnterprises, Tustin, Calif. or F-100, SILPAK, Inc., Pomona, Calif.)ranges from about 10% to about 70% of the total weight. In oneparticular embodiment, the subcutaneous layer is formed with thepercentage of foam at approximately 15%, the percentage of siliconethermoset at approximately 17%, and the percentage of oil (TC-5005 C,BJB Enterprises, Tustin, Calif.) at approximately 68%. The presentinventors have found that this blend creates a layer that accuratelyrepresents the hardness and consistency of the subcutaneous layer. Insome embodiments, the simulated ligamentum flavum is manufactured from aplatinum-cured silicone thermoset with a shore hardness between about 10A and about 50 A. In one embodiment, the ligamentum flavum layer isformed of a silicone thermoset with a shore hardness of 20 A (e.g.,Dragon Skin® 20, Smooth-On, Inc., Easton, Pa.). The lumbar vertebrae aremade of a hard material to realistically represent bone. In oneembodiment, the vertebrae are formed of a castable urethane plastic witha shore hardness of 70 D (e.g., Smooth-Cast® 305, Smooth-On, Inc.,Easton, Pa.). Using a castable urethane plastic can provide advantagesin forming the vertebrae in that it has a low viscosity (so mold-fillingis easy), the final cured part is colored similar to bone without theaddition of pigments, and it has a short de-mold time (approximately 30minute) at room temperature.

The properties of these tissue layers of the epidural/lumbar punctureinsert are critical to the tactile feedback during a needle puncture.Each of the material layers differs in terms of hardness and thickness.The epidural/lumbar puncture insert aims to replicate the feedback whenpuncturing through the skin, subcutaneous, and the ligamentum flavum, soinclusion of the fascia and muscle are not critical. However, in otherembodiments, fascia and muscle layers are included for completeness.

Example 1 Manufacture of Epidural/Lumbar Puncture Insert with Light SkinTone

The following is an example of one method for manufacturing an epiduraland lumbar puncture insert in accordance with the present disclosure. Itis understood that this is provided for illustration and explanation andshould not be considered limiting as to other alternative techniques ofcreating epidural and/or lumbar puncture inserts in accordance with thepresent disclosure.

1. Manufacture Skin Layer:

-   -   a. Clean and assemble the mold, then apply mold release.    -   b. Prepare the Skin Mixture (Material: Dragon Skin 10 Medium)        -   Measure 90 g Part B, add 0.4 g of Silc Pig Fleshtone, add 1            drop (approximately 0.05 mL) of Fuse FX Rosy Skin, add 2            Drops (approximately 0.1 mL) of FuseFX Light Skin, mix until            a uniform color        -   Add 90 g of Part A    -   c. Mix and Vacuum until all bubbles are removed    -   d. Pour the Skin Mixture into the mold (start pouring at the        lowest point). Pour entire contents into the mold.    -   e. Allow to cure for 45 minutes at 66° C.

2. Manufacture Lumbar Vertebrae:

-   -   a. Clean and assemble the mold    -   b. Prepare the Lumbar Mixture (Material: Smooth-Cast® 305)        -   Measure 40 g of Part A, and add 40 g of Part B    -   c. Mix until turns from white to clear    -   d. Pour into silicone mold. When half full, tap silicone mold to        release trapped bubbles then fill to top.    -   e. Completely fill the mold (2 mm before top surface)    -   f. Place in well ventilated location, such as a Fume Hood, to        cure    -   g. Allow to cure for 30 minutes at room temperature (73° F.)

3. Manufacture Fat Layer:

-   -   a. Prepare the Fat Mixture (Materials: Soma Foama, Silicone        99-255, & TC 5005C)        -   Measure 17.5 g of Silicone 99-255 Part A, add 21 g Soma            Foama Part A, add 140 g TC 5005C, mix until uniformly            distributed.        -   Add 17.5 g Silicone 99-255 Part B, add 10.5 g Soma Foama            Part B        -   Mix until bubble formation and reaction begins, and mixture            begins to thicken (approximately 8 minutes at 73° F.).    -   b. Transfer the mixture to the mold, and continue to mix the        material until it starts to set.    -   c. Position the vertebral segment within the locating screws        before the foam mixture has completely set    -   d. Allow to cure for 2 hours at room temperature

Manufacture Ligamentum Flavum:

-   -   a. Prepare the Ligament mixture (Material: Dragon Skin® 20):        -   Measure 60 g Part B, add 2 drops (approximately 0.2 mL) of            Silc Pig Blood, mix until a uniform color        -   Add 60 g Part A    -   b. Mix and Vacuum until all bubbles are removed    -   c. Pour the mixture into the mold making sure to cover the        simulated fat layer at the opening of each vertebral foramen.    -   d. Allow to cure for 4 hours at room temperature (73° F.)

Referring now to FIG. 19, shown therein is a diagrammatic schematic viewof a lung compliance system 600 according to another embodiment of thepresent disclosure. The lung compliance system 600 is configured tosimulate natural lung mechanics. In particular, the lung compliancesystem 600 is configured to simulate the natural lung mechanicsassociated with connecting natural lungs to external ventilators,including positive end-expiratory pressure (PEEP) and assisted-controlventilation. In that regard, PEEP is used to maintain a patient's airwaypressure above atmospheric pressure by exerting pressure that opposespassive emptying of the lungs. PEEP is often used for patients that havea decrease in functional residual capacity of the lungs, which is thevolume of gas that remains in the lung at the end of normal expiration.Functional residual capacity is determined primarily by the elasticcharacteristics of the lungs and chest wall, which is related to lungcompliance. As a general matter, lung compliance is a measure of airvolume change relative to applied pressure change. Lungs that stretchtoo much (too flexible) are said to be high compliance lungs, whereaslungs that stretch too little (too stiff) are said to be low compliancelungs. The lung compliance system 600 facilitates simulation of normal,high, and low compliance lungs. In that regard, the lung compliancesystem 600 increases and decreases the volume capacity of one or moresimulated lungs to replicate natural lung compliance.

As shown, the lung compliance system 600 includes a right lungcompartment 602 and a left lung compartment 604. The right lungcompartment 602 contains a lung 606, a compression bag 608, and asqueezing bag 609, while the left lung compartment 604 contains a lung610, a compression bag 612, and a squeezing bag 613. Each of the lungcompartments 602, 604 define a confined area that contains the lungs606, 610, compression bags 408, 412, and squeezing bags 609, 613,respectively. In some instances, the lung compartments 602, 604 areformed of a fabric, plastic, polymer, or other material having minimalelasticity and/or a predetermined maximum volume such that the lungcompartments 602, 604 do not expand or stretch beyond the maximumvolume, even during inflation and deflation of the lungs 606, 610,compression bags 608, 612, and squeezing bags 609, 613 as discussedbelow. The lungs 606, 610, compression bags 608, 612, and squeezing bags609, 613 are formed of latex or other flexible material that allowsexpansion and contraction of the volume of the lungs, compression bags,and squeezing bags.

The lungs 606, 610 are connected to an airway 614. In particular, theright lung 606 is connected to the airway 614 through a branch 616,while the left lung 610 is connected to the airway 614 through a branch618. The airway 614 leads to an external orifice that is communicationwith an external ventilator 620. In some instances, the airway 614 leadsto an external orifice of a patient simulator, such as a simulated mouthand/or nose. In such instances, the interface or connection between theexternal ventilator 620 and the airway 614 via the external orifice(s)mimics the interface or connection between the external ventilator and anatural patient. In that regard, the external ventilator 620 isgenerally representative of any external ventilator that is utilized inmedical settings. As a general matter the lung compliance system 600 issuitable for use with all types of commercially available ventilators(including bag valve masks, as well as computerized or automatedventilators). Accordingly, the lung compliance system 600 is suitable totrain medical personnel on the proper manner of utilizing the particularventilator(s) used in the hospital or other medical setting in which themedical personnel will be working. Generally, the connections betweenthe external ventilator 620, the airway 614, the branches 616, 618, andthe lungs 606, 610 allow the transfer of air between the externalventilator 620 and the lungs 606, 610 to simulate assisted breathing.

The compression bags 608, 612 and the squeezing bags 609, 613 areconnected to a compressed air source 622. The compression bags 608, 612are connected to the air source 622 via a variable pressure controlvalve 624. In that regard, the variable pressure control valve 624controls the air pressure within the compression bags 608, 612 and,thereby, the corresponding volumes of the compression bags. In thatregard, as the compression bags 608, 612 are expanded the available roomwithin the compartments 602, 604 for the lungs 606, 610 iscorrespondingly reduced. Accordingly, lung compliance is varied byincreasing/decreasing the air pressure inside the compression bags 608,612 to provide the desired amount of available volume within thecompartments 602, 604 for the lungs 606, 610 to expand into. In thatregard, as the pressure inside the bags 608, 612 is increased, thevolume of the compression bags increases, which decreases the availablevolume for the lungs 606, 610, which in turn simulates decreased lungcompliance. On the other hand, as the pressure inside the compressionbags 608, 612 is decreased, the volume of the compression bagsdecreases, which increases the available volume for the lungs 606, 610,which in turn simulates increased lung compliance. Accordingly, byadjusting the pressure and corresponding volume of the compression bags608, 612, the size of lungs 606, 610 is similarly adjusted to simulatelung compliance from High to Normal to Low.

The squeezing bags 609, 613 are connected to the air source 622 via avalve 626. Valve 626 controls the flow of air to the squeezing bags 609,613. In that regard, the inflation of the squeezing bags 609, 613 issynchronized with the respiratory cycle of the simulator. Morespecifically, the squeezing bags 609, 613 are inflated with expirationand deflated with inspiration. In some instances a pressure sensor 627in communication with airway 614 is utilized to monitor expiration andinspiration pattern of the ventilator. In that regard, an increase inpressure is associated with inspiration, while a decrease in pressure isassociated with expiration. Inflation of the squeezing bags 609, 613reduces (along with the compression bags 608, 612) the available volumefor the lungs 606, 610 within the lung compartments 602, 604, whichassists in forcing air out of the lungs 606, 610 (simulating exhaling).On the other hand, deflation of the squeezing bags 609, 613 increasesthe available volume for the lungs 606, 610 within the lung compartments602, 604, which assists in allowing air into the lungs 606, 610(simulating inhaling). When inflated the squeezing bags 609, 613 alongwith the compression bags 608, 612 define the available volume remainingin the compartments for the lungs 606, 610. Accordingly, in someinstances inflation of the squeezing bags 609, 613 and compression bags608, 612 are controlled in a manner that defines the functional residualcapacity of the lungs 606, 610. This allows the lung system 600 to beutilized with positive end-expiratory pressure (PEEP) aspects of theexternal ventilator 620.

The lung compliance system 600 is also configured to simulate CO₂exhalation while keeping the simulator mobile. In that regard, previoussystems have relied upon external CO₂ sources such as canisters (toolarge to fit inside a patient simulator) or lines (located a fixedlocation) that limit the mobility of the simulator. In contrast, thelung compliance system 600 includes a CO₂ system 628 that is easilyplaced within a patient simulator. In that regard, the CO₂ system 628includes a miniature CO₂ canister 630, a pressure regulator 632, and avalve 634 that are in communication with the airway 614. In someembodiments, the CO₂ canister 630 holds between about 2 g to about 250 gof CO₂. In that regard, in some instances the CO₂ canister 630 is acommercially available CO₂ canister similar to those utilized fornumerous recreational purposes (e.g., refilling bicycle tires, paintballguns, etc.). The pressure regulator 632 reduces the pressure from theCO₂ canister 630. In some instances, the pressure regulator 632 reducesthe pressure to approximately 3 psi. The valve 634 opens in coordinationwith the respiratory cycle of the simulator such that a small amount ofCO₂ is released with each exhale of the simulator.

The lung compliance system 600 is also configured to work withassist-controlled aspects of the external ventilator 620. In thatregard, the lung compliance system is able to trigger the ventilator tocause the ventilator to assist the simulator in breathing.Assist-controlled ventilation is used on patients that are trying tobreathe on their own but are still too weak to breathe on their own.Accordingly, the ventilator 620 is utilized to help the patient breathwhen it senses the patient's natural breathing is insufficient. Withrespect to lung compliance system 600, an air flow system 636 isutilized to simulate the patient's natural breathing in a manner thatcan be used with the assist-controlled aspects of a ventilator. In thatregard, the air flow system includes a vacuum tank 638, a compressor,640, a vacuum valve 644, and a check valve 646. In use, the compressor640 extracts air from the vacuum tank 638, which is passed through thecheck valve 646 and into airway 614. In that regard, check valve 646 isa one-way valve such that air can only go from compressor 640 outtowards airway 614. Coordinated with the respiration rate of thesimulator, the vacuum valve 644 connects the airway 614 with the vacuumtank 638. By connecting the airway 614 to the vacuum tank 638, air isremoved from the airway 614. This is utilized to trigger the assistfunction of the ventilator 620. In that regard, many ventilators monitorthe amount of air into and out of the patient. If it is determined thatthe amounts are not equal, the ventilator will sound an alarm.Accordingly, the air flow system 636 is a closed loop system to ensurethat the amount of air coming into the simulator is the same as theamount of air going out from the simulator. In that regard, airextracted from the vacuum tank 638 goes into the airways of thesimulator (including branches 616, 618 and lungs 606, 610, in someinstances), and when the vacuum tank 638 is connected with the airwaysvia the vacuum valve 644, air from the airways fill the vacuum tank.

While the lung compliance system 600 is shown as having right and leftlung compartments, in other embodiments the system includes only asingle lung compartment. Further, while the compression bags 608, 612are shown as being connected to a single control valve 624, it isunderstood that the pressure within each of the compression bags 608,612 is controlled separately in some instances. In some such instances,the system includes a pair of control valves, each associated with oneof the compression bags. Alternatively, the single control valve 624 mayhave two or more outputs that are individually controlled to allowseparate control of the pressures within the compressions bags 608, 612.Similarly, the squeezing bags 609, 613 may be independently controlledusing one or more valves. Further still, in some embodiments thecompression bags 608, 612 and/or the squeezing bags 609, 613 are filledwith a liquid, instead of air or other gas. In other embodiments, thecompression bags 608, 612 and/or the squeezing bags 609, 613 arereplaced with a movable member that selectively increases/decreases theavailable volume within lung compartments 602, 604 for the lungs 606,610. For example, in one embodiment each of the lung compartments 602,604 includes one or more movable walls, where each wall is connected toa motor, pneumatic valve, or other actuator that controls the positionof the wall within the lung compartment. Movement of the wallselectively increases or decreases the volume within the lungcompartment and/or assists in lung deflation/inflation.

Although illustrative embodiments have been shown and described, a widerange of modification, change, and substitution is contemplated in theforegoing disclosure and in some instances, some features of the presentdisclosure may be employed without a corresponding use of the otherfeatures. It is understood that such variations may be made in theforegoing without departing from the scope of the embodiment.Accordingly, it is appropriate that the appended claims be construedbroadly and in a manner consistent with the scope of the presentdisclosure.

What is claimed is:
 1. A method of teaching patient care, the methodcomprising: providing a lung compliance simulation system including: alung compartment; a simulated lung positioned within the lungcompartment, the simulated lung being inflatable and deflatable; and asqueezing bag positioned within the lung compartment, wherein thesqueezing bag is configured to inflate with exhalation and deflate withinhalation; wherein the lung compartment defines an available volume forthe simulated lung to expand into and wherein the available volume forthe simulated lung to expand into is adjustable to control a complianceof the simulated lung; coupling an external ventilator to the lungcompliance simulation system; and activating the external ventilatorwhile coupled to the lung compliance simulation system such that thelung compliance simulation system simulates natural lung mechanics. 2.The method of claim 1, wherein the activating the external ventilatorincludes generating positive end-expiratory pressure (PEEP).
 3. Themethod of claim 1, wherein the activating the external ventilatorincludes providing assisted-control ventilation.
 4. The method of claim1, further comprising adjusting the compliance of the simulated lung. 5.The method of claim 4, wherein the adjusting the compliance of thesimulated lung includes adjusting a volume of a compression bagpositioned within the lung compartment.
 6. The method of claim 5,wherein the compliance of the simulated lung decreases with an increasein the volume of the compression bag.
 7. The method of claim 1, whereinthe external ventilator is an automated ventilator.
 8. The method ofclaim 1, wherein the external ventilator is a manual ventilator.
 9. Themethod of claim 1, further comprising simulating a CO₂ exhalation withthe lung compliance simulation system.
 10. The method of claim 1,wherein the lung compliance simulation system includes right and leftlung simulations.
 11. The method of claim 10, further comprisingsimulating a first lung scenario with the right lung and a second lungscenario with the left lung.
 12. The method of claim 11, wherein thefirst lung scenario is different than the second lung scenario.
 13. Themethod of claim 12, wherein the first lung scenario is a first lungcompliance and the second lung scenario is a second lung compliance. 14.A method of teaching patient care, the method comprising: providing alung compartment defining a maximum volume; positioning a first bagwithin the lung compartment, the first bag being inflatable anddeflatable to simulate functioning of a natural lung; positioning asecond bag within the lung compartment adjacent to the first bag; andselectively inflating and deflating the second bag to occupy varyingamounts of the maximum volume in order to control a simulated lungcompliance of the first bag.
 15. The method of claim 14, whereininflating the second bag decreases the simulated lung compliance of thefirst bag.
 16. The method of claim 14, wherein deflating the second bagincreases the simulated lung compliance of the first bag.
 17. The methodof claim 14, further comprising: positioning a third bag within the lungcompartment; and inflating the third bag during simulated exhalation anddeflating the third bag during simulated inhalation.
 18. The method ofclaim 17, further comprising controlling the inflation and deflation ofthe second and third bags to define a simulated functional residualcapacity suitable for use with a positive end-expiratory pressure (PEEP)ventilator.
 19. The method of claim 14, further comprising positioningthe lung compartment within a torso of a patient simulator.
 20. Themethod of claim 19, wherein the patient simulator is a full bodysimulator.